Retractable sensor for an alarm system

ABSTRACT

A retractable sensor assembly for use with an alarm system to prevent theft of valuable products while eliminating the problem of entangled and unsightly sensor cords is disclosed. The retractable sensor allows the user to grasp the product and pull it to a comfortable position. The invention consists of a housing, a retraction means contained in the housing, a sensor having two states, 1) secured when attached to the product and 2) unsecured when detached from the product, a multiconductor cable having a first end connected to the sensor, cooperating with the retraction means and a second end extending out of the housing, where the retraction means urges the sensor to the housing, yet allows the sensor to be pulled from the housing when an external force is exerted on the sensor, while maintaining a continuous electrical path from the first, sensor end of the cable to the second end of the cable.

FIELD OF THE INVENTION

The present invention relates to security alarms and anti-theft devicesand, particularly, to an improved sensor design which allows limitedfreedom of movement of a consumer item to which it is attached.

BACKGROUND OF THE INVENTION

In recent years, retail and wholesale merchandisers have directedsubstantial attention to the nagging and costly problem associated withthe theft and/or damage of costly display products on their premises.With the advent of smaller and more portable electronic apparatus, theease with which pilferers and shoplifters can quickly and easily removesuch goods from display cases and display racks has intensified. At thesame time, the availability of new products, such as video cassetterecorders, small portable radios and televisions, calculators and thelike has skyrocketed, resulting in more and more valuable products beingtaken or tampered with. As locks and other security devices have becomemore sophisticated, so too have the individuals and methods forcircumventing the operation of conventional security devices and,particularly, alarm sensing devices. The alarm system described in U.S.Pat. No. 5,172,098, to Leyden, has solved many of these problems. Someproducts, such as remote controls, are designed to be held and movedabout. A sensor which can move freely with the product for a limiteddistance but returns the product and sensor to a set position when notbeing handled by a customer is optimal.

SUMMARY OF THE INVENTION

The above invention is specifically directed to overcoming the aboveproblems in a novel and simple manner. The invention is particularlydirected to use with remote controls but is not limited to this use.

According to the present invention, a retractable sensor is provided foruse with an alarm system to prevent the theft of valuable products, suchas video cassette recorders, small portable radios and televisions. Theretractable sensor consists of a housing, a retraction device containedin the housing, a sensor having two states, 1) secured when attached tothe product and 2) unsecured when detached from the product, and amulticonductor cable with one end attached to the sensor, then extendinginto the housing, cooperating with the retraction device and the secondend extending out of the housing, the retraction device urging thesensor to the housing, yet allowing the sensor to be pulled from thehousing when an external force is exerted on the sensor whilemaintaining a continuous electrical path from the first end to thesecond end of the cable.

Preferably, the sensor has an indicating device on its housing fordisplaying the state of the sensor. In a highly preferred form, theindicator is a light-emitting diode.

One embodiment uses a phone cord as the multiconductor cord.

Preferably the second end of the cable contains a connecting device tomate with an alarm system, such as the alarm system described in U.S.Pat. No. 5,172,098.

A preferred form of the invention has a retraction structure consistingof a spool mounted for rotation in the housing on which themulticonductor cable is wound and a device operatively associated withthe spool for urging the spool in a direction to wind the cable onto thespool, yet permitting the unwinding of the cable when a user pulls theproduct, attached to the cable by the sensor, away from the housing.

With the above apparatus, the user can grasp and pull a product to acomfortable position. But if the user attempts to detach the productfrom the sensor, the alarm system detects this and warns the merchant.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial perspective view of a shelf with an electronicdevice thereon, a remote control for operating the electronic device anda retractable sensor according to the present invention attached to theremote control for allowing movement of the remote control from thesolid position of FIG. 1 to the phantom line position;

FIG. 2 is an enlarged perspective view of the retractable sensoraccording to the present invention;

FIG. 3 is a top view of the retractable sensor with a remote controlattached thereto and shown in phantom;

FIG. 4 is a sectional view of the retractable sensor taken along line4—4 of FIG. 3;

FIG. 5 is a sectional view of the retractable sensor taken along line5—5 of FIG. 4;

FIG. 6 is a side view of the pulley as used in the retractable sensor ofthe present invention;

FIG. 7 is a perspective view of an alarm system which cooperates withthe retractable sensor of the present invention:

FIG. 8 is a partial schematic view of the retractable sensor showing oneembodiment of the sensor; and

FIG. 9 is a schematic view of the alarm system shown in FIG. 7.

DETAILED DESCRIPTION OF THE DRAWINGS

The disclosed invention is shown as used with a remote control for anelectronic device. The invention can be used with a wide variety ofproducts and the choice of a remote control is just for convenience. Itis understood that the particular product used to illustrate theinvention is shown by way of example only and not as a limitation of theinvention.

In FIG. 1, a typical point-of-purchase display is shown at 10 for anelectronic device 12 which is operable through a portable, hand-heldcontrol 14 from a location remote from the device 12. A display shelf 16defines an upwardly-facing surface 18 for supporting the device 12. Theshelf 16 has a peripheral, vertically- extending edge 20 to which theremote control 14 is attached through a retractable sensor assembly 22,according to the present invention. The retractable sensor assembly 22is designed to allow free movement of the remote control 14 thereon fromthe stored/solid line position of FIG. 1, to the phantom position inFIG. 1, wherein it can be conveniently manipulated by the consumer.

The details of the retractable sensor assembly 22 are shown in FIGS.2-6. The retractable sensor assembly 22 consists of a rectangularhousing 24 defined by first, and second housing parts 26, 28respectively. The first and second housing parts 26, 28, operativelyconnected as in FIGS. 2-4, define an internal space 30 which contains aretraction mechanism at 32 for a multiconductor cable 34, see FIG. 4. Asensor 35 is connected to the cable 34 and attaches to the remotecontrol 14. For a description of several methods of attaching the sensorto a product, see U.S. Pat. No. 5,172,098 which is incorporated hereinby reference.

The first and second housing parts 26, 28 are held together by aplurality of screws 36. To facilitate anchoring of the housing 24,flanges 38, 40 are integrally formed thereon and have openings 42therein to accept conventional fasteners, such as screws and nails 44(FIG. 1).

A plurality of threaded posts 78 are provided for the screws 36 tosecure the two housing parts 26, 28. The posts 78 are made of twohalves, one half extending from housing part 26 and the other halfextending from housing part 28 and meeting in the middle.

The retraction mechanism 32 has a double pulley 46, with a top disk 48,middle disk 50 and bottom disk 52. The double pulley 46 has three hubswith three different radii, a sensor hub 54, a recoil hub 56 and analarm system hub 58. In the preferred embodiment the radius of the alarmsystem hub 58 is smaller than the sensor hub 54. The double pulley 46has a tube 60 running through the center of the hubs 54, 56, 58, asshown in FIG. 5. The double pulley 46 rotates around a rod 62 (see FIG.4) which is formed by a male post 64, attached to the housing part 28,mating with a female post 66, attached to the housing part 26.

A coil spring 68 attaches to the double pulley 46 at the recoil hub 56.In an embodiment, the coil spring 68 has a T-shaped end (not shown)which is inserted in a slot 70 in the recoil hub 56. The end is thenrotated so that it cannot be removed from the slot 70.

The coil spring 68 sits in a circular cup 72. The cup has an opening 74through which the end of the coil spring 68 extends out onto the recoilhub 56. When the coil spring 68 is placed in the cup 72, it expandsuntil it meets an interior surface 76 of the cup 72, where it is held.The opening 74 is chosen so that the coil spring 68 cannot pass throughthe opening 74 when the sensor 35 is fully extended.

The cable 34 is continuous through the housing 24, from the sensor 35 toa phone plug 80. From the sensor 35 the cable 34 winds around andspirals into the sensor hub 54. Then the cable 34 extends through a hole82 (shown in FIGS. 4-6), near the edge of sensor hub 54, in middle disk50 where the cable 34 winds around and spirals out from the alarm systemhub 58, and then extends out of the housing 24 to the phone plug 80. Thecable 34 is wrapped on the sensor hub 54 and the alarm system hub 58 insuch a way that when the sensor 35 is pulled from the housing 24, thecable 34 unwinds around the alarm system hub 58 (i.e. the cable 34unwinds from the hubs 54, 58 simultaneously). This unwinding results inthe cable 34 forming a looser spiral around the alarm system hub 58. Thecable 34 is prevented from extending out towards the phone plug 80 by aU-shaped catch 84. The catch 84 is designed so that cable 34 tightlyengages the catch 84.

The retractable sensor assembly 22 is designed to work with an alarmsystem 200 of FIG. 7. The retractable sensor assembly 22 has a cable 34that mates with a splitter box 202 of the alarm system 200. The detailsof the alarm system are described in U.S. Pat. No. 5,172,098.

Each splitter box 202 can control up to six sensors 204 as best seen inFIG. 9. The splitter boxes 202 can be daisy-chained to add additionalsensors 204. The sensors 204 can be the retractable sensor assembly 22disclosed herein or any of the variety of sensors described in U.S. Pat.No. 5,172,098.

The alarm system 200 includes an alarm housing 210 enclosing an alarmcircuit 212 having a horn 214. A lock 216 enables and disables the alarmcircuit 212 via a key (not shown). An AC adapter 218 provides a ninevolt DC voltage from a 110 VAC source. The electrical cord 220 connectsthe alarm circuit 212 to the splitter box 202. The alarm housing 210also includes an LED 222 in addition to the horn 214 to indicate thestate of the alarm circuit 212. The electrical cord 220 may consist of aphone cord and include a connector 224 (one shown), one from thesplitter box 202 and the other form the alarm circuit 212.

FIG. 8 shows a schematic view of the sensor 35. When the sensor 35 isadhered to the remote control 14 the button 160 is depressed as shown inFIG. 8 and FIG 3. The depression of button 160 causes a first conductor161 to come into contact with a second conductor 163 to complete anelectrical circuit. Due to the completion of the electrical circuit, adetector circuit 201, contained in the splitter box 202 (as shown inFIG. 7), determines that the sensor 35 is attached to the remote control14. The detector circuit 201 is described in U.S. Pat. No. 5,172,098which is incorporated by reference herein. The detector circuit 201induces an electrical current to flow in one direction through indicator164. Since the indicator 164 has two LED's 165,167 connected inantiparallel, one of the LED's 165 is conducting and emits red light.The red light indicates the sensor 35 is in the secured state.Alternatively, when the sensor 35 is removed from the remote control,the button 160 is released and the first conductor 161 breaks contactwith the second conductor 163 to break the electrical circuit. Thedetector circuit 201 induces an electrical current to flow in a seconddirection through the indicator 164. This results in LED 167 conductingand emitting a green light, which indicates the sensor 35 is in theunsecured state.

With the above structure, it can be seen that consumers can convenientlygrasp the remote control 14 and operate it in a normal manner. At thesame time, the merchant is afforded the security of knowing that theremote control 14 cannot be removed from the premises. The device can bemade sufficiently low in cost that it can be affordably purchased andused for even low-price remote controls.

The foregoing disclosure of specific embodiments is intended to beillustrative of the broad concepts comprehended by the invention and isnot intended to limit the scope of the invention.

We claim:
 1. A retractable sensor assembly, as used with an alarmsystem, comprising; a housing; means for retraction contained in saidhousing; a sensor having two states, 1) secured when attached to aproduct and 2) unsecured when detached from said product, said sensorbeing outside the housing; a multiconductor cable, having a first endattached to the sensor then extending into the housing, cooperating withthe retraction means and a second end extending out of the housing; saidretraction means urging the cable into the housing and thereby urgingthe sensor to the retraction means, yet allowing the sensor to be pulledfrom the housing when an external force is exerted on the sensor, whilemaintaining a continuous electrical path from the first, sensor end ofthe cable to the second end of the cable; and means for connecting saidsecond end of the cable to an alarm system able to detect if said sensoris in the secured or unsecured state, whereby a user can grasp and pullon a product attached to the sensor to place the product in acomfortable position, but if the user detaches the product from thesensor the alarm system detects the unsecured state.
 2. The retractablesensor assembly of claim 1 wherein said sensor has an indicating meansfor indicating the state of the sensor.
 3. The retractable sensorassembly of claim 2 wherein said indicating means is a light-emittingdiode.
 4. The retractable sensor assembly of claim 1 wherein saidmulticonductor cable is a phone cord.
 5. The retractable sensor assemblyof claim 1 wherein said retraction means includes; a spool mounted inthe housing upon which said multiconductor cable is wound; and biasingmeans operatively associated with said spool in said housing for urgingsaid spool in a direction to wind the cable on the spool, yet to permitunwinding of the cable when an external force is exerted on the sensor.6. A retractable sensor assembly, as used with an alarm system,comprising; a housing; a pulley mounted for rotation in said housing,having a pair of hubs, a sensor hub and an alarm system hub, and a diskbetween the sensor and the alarm system hub has a hole; a multiconductorcable wound about the sensor hub through said hole in said disk and thenwound around the alarm system hub of said pulley, the cable havingopposite near and remote ends; a sensor, outside the housing, connectedto the remote end of said cable and being attachable to a product, saidsensor having two states, 1) secured when attached to the product and 2)unsecured when detached from the product, and the sensor including meansfor electrically connecting or disconnecting conductors in said cableaccording to the state of the sensor; biasing means operativelyassociated with said pulley in said housing for urging said pulley andthe pair of hubs in a direction to wind the cable around the sensor huband thereby pull the sensor to the housing yet to permit the sensor toextend from the housing when an external force is exerted on the sensor;and a connector, outside the housing, attached to the near end of thecable, for connecting to an alarm system, whereby a user can grasp andpull on a product attached to the sensor to place the product in acomfortable position, but if the user detaches the product from thesensor the alarm system detects the unsecured state.
 7. The retractablesensor assembly of claim 6 wherein said sensor includes a means forvisually indicating whether the sensor is in the secured or unsecuredstate.
 8. The retractable sensor assembly of claim 7 wherein saidindicating means is a light-emitting diode.
 9. The retractable sensorassembly of claim 6 in combination with a product and including meansfor attaching the sensor to the product so that the sensor is in thesecured state.
 10. The retractable sensor assembly of claim 9 whereinthe sensor and cable are the only elements connecting between theproduct and housing.
 11. A retractable cable assembly, as used with analarm system, comprising; a housing; means for retraction contained insaid housing; a multiconductor cable, having a first end attached to asensor attachable to a product then extending into the housing,cooperating with the retraction means and a second end extending out ofthe housing, said sensor having two states, 1) secured when attached tothe product with at least two conductors of the cable electricallyconnected and 2 ) unsecured when detached from the product with said atleast two conductors electrically disconnected; said retraction meansurging the cable into the housing and thereby urging the first endconnected to a product the sensor to the retraction means, yet allowingthe first end to be pulled from the housing when an external force isexerted on the first end, while maintaining a continuous electrical pathin said at least two conductors from the first end of the cable to thesecond end of the cable; and means for connecting the second end of thecable to an alarm system which detects a) a the secured state with theelectrical path continuous between the first and second ends of thecable at least two conductors of the cable electrically connected and b)an unsecured state with the continuity of the electrical path betweenthe first and second cable ends broken at least two conductors of thecable electrically disconnected, whereby a user can grasp and pull on aproduct attached to the first cable end to place the product in acomfortable position, but if the user breaks the continuity of theelectrical path electric connection of the at least two conductors ofthe cable the alarm system detects the unsecured state.
 12. Aretractable cable assembly, as used with an alarm system, comprising; ahousing; a cable having first and second conductors extending betweenopposite first and second ends of said cable; means for attaching saidcable first end to a product; means for electrically connecting saidfirst and second conductors at said first end of said cable whereby 1 )said first and second conductors form an alarm loop extending from saidcable second end through said first conductor to said cable first endand back through said second conductor to said cable second end whensaid attaching means attach said cable to a product and 2 ) said alarmloop is broken by detaching said cable from a product; a connector forconnecting said cable second end to an alarm system responsive to anybreak of the alarm loop; and a retracting mechanism in said housingcontinuously urging the cable first end toward the housing yet allowingthe cable first end to be pulled away from the housing when an externalforce is exerted on the cable first end.
 13. The retractable cableassembly of claim 12, wherein said retracting mechanism continuouslyurges the cable first end toward the housing, whereby a user can graspand pull on a product attached to the cable first end to place theproduct in a comfortable position with a minimum amount of cableextending from said housing.
 14. The retractable cable assembly of claim13, wherein said retracting mechanism comprises: a pulley mounted forfree rotation relative to said housing and including a sensor hub and analarm system hub separated by a disk, said disk having a hole therein,whereby said cable extends from said cable first end into said housingwhere it winds around said sensor hub then extends through said pulleydisk hole and winds about said alarm system hub then extends from saidhousing to said cable second end; and a spring continuously biasing saidpulley toward winding said cable onto said sensor hub.